Magnetic mesostructure of giant magnetostrictive spring magnet type multilayers

The magnetic behavior of giant magnetostrictive TbFe/FeCo multilayers show that individual layers of as-deposited multilayers in their demagnetized st ate are single domain due to stray-field coupling between adjacent layers. Such multilayers do not show a collective behavior during magnetization rev ersal. In contrast, stress-free films obtained by annealing at 543 K for 1 h subdivide themselves into multiple domains to lower their overall energy, and show a collective magnetization behavior. An interesting observation i s the dynamic formation and collapse of magnetoelastically induced domains in TbFe layers in annealed multilayers during reversal. (C) 1999 American I nstitute of Physics. [S0021-8979(99)43808-3].